we were at Aulani for 7 days last November (week before thanksgiving,which was what I hear low season) and bought a 4 day Go Oahu from Costco.
We did pre-book luau reservations at the PCC a few weeks before our trip. In addition to PCC we used it for:
- Wailua swim to waterfall (pretty hike on paved trail, swim to waterfall in lagoon)
- Dole Plantation (train & maze, skipped garden tour although it was also included)
- Sea Life Park (don't miss - if DD was older we would have used the premium experience for the swim w/ the dolphins instead of PCC luau)
- Wet & Wild (10 min drive from Aulani)
It was very easy to use the card (I actually printed out the cards from my computer before leaving) but if you are staying at Aulani for less than a week I'd say just play it by ear and go places day by day w/o the stress of needing to use a pass.
I do wish we had gotten to PCC earlier in the day - we did Dole & Wailua first so by the time we got to PCC we only had an hour or so to check out the villages and exhibits before the luau started. We (and DD6) were too pooped after the luau for the evening show which was also included although the luau was entertaining enough for us.